In conventional multi-product production, a product is managed in each kind, and the production is performed while a manufacturing process is rearranged each time by monitoring an order reception state and an order reception prediction of each product kind. However, in this method, a man-hour in the rearrangement and tuning of the device increases extremely in the case that the kind of the product to be produced increases extremely while the order reception state is unstable, or in the case that on-demand production is performed without the order reception prediction (product varies individually).
In “radio IC tag utilizing multi-product automatic production system with radio PLC” proposed by Patent Document 1, in which the kind of the product is identified by reading tag information from a radio IC tag attached to a workpiece and a work program for the device on a production line is automatically changed.
However, in the conventional technology of Patent Document 1, it is necessary that a user program, an image processing item, and tuning setting value be previously stored in a PLC, an image sensor, and a robot with respect to all the presumed products, and it is necessary that the production line be automatically re-tuned each time by acquiring identification information about each product at the beginning of the process. Therefore, the tuning can hardly be performed when an unknown product that is not presumed in each device flows in the process.
In “RFID (Radio Frequency IDentification) system and RFID tag” proposed by Patent Document 2, not only a product kind but also a content to be performed are stored in a radio IC tag. In the RFID system of Patent Document 2, product- or component-associated information such as a work content and a test result is sequentially written in the RFID tag, and a state of the product or component to which the RFID tag is attached is managed by referring to data stored in the RFID tag (see paragraph number [0002] of Patent Document 2). That is, the test data is stored in the radio IC tag or RFID.
However, because a memory capacity is restricted in an inexpensive radio IC tag, it is difficult to directly store a large amount of data. On the other hand, the use of a large-capacity radio IC tag leads to a substantial increase in cost.
In “production management system and quartz oscillator” proposed by Patent Document 3, all the pieces of test data are stored in a server while paired with the identification information about the radio IC tag, and the test data stored in the server can be referred to by accessing the server in a subsequent process using the identification information about the radio IC tag.
On the other hand, in “information system and method thereof” proposed by Patent Document 4, pieces of information about the products or services supplied by plural manufacturers are stored in a central database, each product includes an identifier such as the RFID, and a customer reads the identifier to access the central database, which allows the customer to obtain the information about each product.